<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	c
	<script type="text/javascript">
		function goBackOne() {
			window.history.go(-1);
		}
		function goBack() {
			window.history.go(-2);
		}
	</script>
	<a href="09c.html">c</a>
	<input type="button" value="后退" onclick="goBackOne()" />
	<input type="button" value="后退2步"  onclick="goBack()" />
</body>
</html>